1. Field of the Invention
The present invention relates to a stretchable pressure-sensitive adhesive sheet.
2. Description of the Related Art
In general, pressure-sensitive adhesive (or PSA; the same applies hereinafter) has characteristics to be in a soft solid (viscoelastic) state in a room temperature range and adhere to adherend under some pressure. For such advantageous characteristics, PSA has been preferably used, for instance, in a form of a substrate-supported PSA sheet having a PSA layer at least on one face of a substrate, for fixing components in mobile electronics such as mobile phones, smartphones, tablet PCs, etc. PSA sheets with film-like substrates have certain mechanical strength and are less susceptible to damage such as fracture, etc. Thus, they are preferably used as PSA sheets that are removed after adhered. Literatures disclosing this type of conventional art include Japanese Patent Application Publication No. H6-346032 and Japanese Patent Application Publication (Translation of PCT International Application) No. 2005-500133. Both Japanese Patent Application Publication Nos. H6-346032 and 2005-500133 disclose conventional inventions comprising stretchable substrates. Japanese Patent Application Publication No. 2005-500133 relates to a medical PSA sheet applied to skin.